A driver accused of running a Massachusetts stop sign and causing an ambulance crash that killed a patient is being charged with negligent motor vehicle homicide.

Driver: Lisa Zemack, 61, drove through a stop sign, hitting an ambulance and killing a dialysis patient who was being transported

A spokesman for Worcester District Attorney Joseph Early said Wednesday that Lisa Zemack, 61, also faces a charge of driving to endanger in connection with the crash a day earlier in Milford, 40 miles southwest of Boston.

Zemack, a local real estate agent, will be summoned to court at a later date.

Police say the patient in the ambulance was 58-year-old Upton resident Karen Scott.